1. Field of the Invention
The present invention relates to an image-forming device capable of feeding paper smoothly.
2. Related Art
One conventional construction for a paper supply section used in a printer or other image-forming device is disclosed in Japanese unexamined patent application publication No. HEI-9-278196. The paper supply section of this image-forming device includes a pickup roller for feeding the topmost sheet of paper stacked on a stacking plate, a conveying roller disposed downstream of the pickup roller, and a reverse roller disposed in contact with the conveying roller. The reverse roller is also referred to as a retard roller.
The pickup roller, the conveying roller, and the reverse roller together constitute a separating/feeding section for separating and feeding the stacked sheets of paper one sheet at a time. The paper supply section further includes a lifter for urging the stacking plate toward the separating/feeding section.
The lifter is driven at a timing in which the pickup roller is withdrawn above the sheets of paper. In other words, the stacking plate is raised during a time that paper is not being fed. As a result, this construction can stably feed paper without variations in the amount of frictional force that the pickup roller applies to the paper.
With the image-forming device described above, there has been demand for increasing the paper feeding speed and reducing the gap between fed sheets of paper in order to shorten the printing time when printing a plurality of sheets of paper one sheet after another (multiple page printing).
Hence, the time during which paper is not being fed has become increasingly shorter in recent years. Accordingly, when constructing a paper supply section as described above, it is no longer possible to secure sufficient time when paper is not being fed in order to drive the lifter to raise the paper stacking plate when the amount of stacked paper has decreased, leading to problems in paper feeding.